Pressure-flushing cistern for a water closet

ABSTRACT

The pressure-flushing cistern comprises a pressure tank ( 2 ), an actuating device for initiating a flush and also a pressure-reducing valve ( 27 ), which is to be connected to a water pipe and via which the pressure tank ( 2 ) can be filled with flushing water. The closing pressure of the pressure-reducing valve ( 27 ) is adjustable with a displaceable ring ( 17 ). The ring ( 17 ) can be gripped from outside through a window ( 19 ) of a housing ( 6 ) for adjusting the closing pressure. Adjustment preferably takes place by steps.

The invention relates to a pressure-flushing cistern for a water closet,with a pressure tank, an actuating device for initiating a flush, apressure-regulating valve, which is to be connected to a water pipe andby means of which the pressure tank can be filled with flushing water,and with an outlet valve.

A pressure-flushing cistern of this kind has become known in the priorart from WO 98/39522, for example. Pressure-flushing cisterns of thiskind have the advantage that they make effective cleaning of the watercloset bowl possible with relatively low water consumption. The pressuretank is filled with flushing water by means of a water pipe connected tothe pressure-flushing cistern. During this operation, air present in thepressure tank is compressed. If the outlet valve is opened, flushingwater is discharged into the water closet bowl as the air expands. Theoutlet valve is designed as a piston and closes the outlet valve whenthe flushing water has flowed out.

A further component of the pressure-flushing cistern is what is known asthe system separator, which prevents flushing water being sucked fromthe pressure tank into the supply line in the event of low pressure inthe water pipe. Such a system separator (vacuum breaker) is disclosed inthe said WO 98/39522.

In order that a predetermined pressure is not exceeded in the pressuretank after it has been filled, a pressure-reducing valve is provided,which limits the maximum pressure. In the case of the pressure-flushingcistern mentioned above, this pressure-reducing valve comprises a pistonwhich is subjected to the pressure in the pressure tank and closes themouth of a nozzle counter to the reacting force of a spring. When thepressure in the pressure tank falls during flushing, the piston of thepressure-reducing valve is displaced owing to a pressure difference onthe piston, and the inlet valve is thus opened. Water flows into thepressure tank through the opened mouth of the nozzle. When apredetermined pressure in the pressure tank is reached, thepressure-reducing valve closes. The designated maximum pressure in thepressure tank can be changed by exchanging the said spring. A strongerspring results in a higher pressure and a weaker spring a lowerpressure. However, such an exchange of the spring is relativelyinvolved.

The invention is based on the object of producing a pressure-flushingcistern of the said kind which makes possible simpler change-over to adifferent maximum pressure in the pressure tank.

The object is achieved in a pressure-flushing cistern of the generictype characterized in that the closing pressure of thepressure-regulating valve is adjustable.

According to a development of the invention, the closing pressure of acounterpressure spring of the pressure-reducing valve is adjustable.According to a development of the invention, this can be effectedespecially simply constructionally and also in a user-friendly way whenthe pressure spring can be adjusted with an adjusting ring, theadjusting ring forming a counterbearing for the spring.

The valve housing of the inlet valve is preferably of laterally opendesign, so that the adjusting ring can be reached and displaced fromoutside. Recesses in the form of steps, which in each case correspond toan adjusted position of the adjusting ring, are preferably arranged onthe valve housing. For example, one such step corresponds to an internalpressure of 1.5 bar, a second recess to an internal pressure of 2 barand another recess to an internal pressure of 2.5 bar.

According to a development of the invention, the adjusting ringcomprises holding projections for its stepped displacement. Theseholding projections are accessible from outside and are in each casefixed in a corresponding recess of the valve housing. A version in whichthe adjusting means, or the adjusting ring, is continuously displaceableis also conceivable.

A particularly simple and cost-effective construction is brought aboutwhen the pressure-reducing valve is arranged at the outlet of a systemseparator. According to an advantageous development of the invention,the said adjusting ring is arranged axially displaceably on theperiphery of a nozzle body of the pressure-reducing valve.

Further advantageous features emerge from the dependent patent claims,the description below and the drawing.

An illustrative embodiment of the invention is explained in greaterdetail with reference to the drawing, in which:

FIG. 1 shows a vertical section through part of the pressure-flushingcistern according to the invention, the inlet valve being open;

FIG. 2 shows a section according to FIG. 1, but with the inlet valveclosed;

FIG. 3 shows a section through the inlet valve and the reducing valve,the inlet valve being closed;

FIG. 4 shows a section according to FIG. 3, but with the inlet valveopen, and

FIGS. 5 to 7 show part views of the pressure-flushing cistern withdifferent settings of the closing pressure.

The pressure-flushing cistern 1 has a pressure tank 2, shown only inpart in FIG. 1, which has a pressure space 3 which is filled withflushing water via a pressure-reducing valve 27. For the supply of theflushing water, the pressure-flushing cistern 1 is connected to apressure water pipe (not shown here) at a connection neck 5 of a systemseparator 25. The per se known system separator 25 is provided forreasons of safety and prevents water passing from the pressure tank 2into the supply line in the event of low pressure. Such systemseparators are regulation in many countries and known per se.

The system separator 25 comprises a housing 6 which at a lower end formsa horizontally extending nozzle body 21. A channel 15 with a mouth 4likewise extends horizontally in the nozzle body 21.

The nozzle body 21 is part of a pressure-reducing valve 27 which isarranged at the outlet of the system separator 25. The pressure-reducingvalve 27 has a cap-shaped housing 7, which is inserted into an opening31 of the housing 6. The connection of the housing, 7 to the housing 6can be designed as a bayonet or screw connection, for example. Thehousing 7 has at one end an opening 8, which leads into a pipe 30 andfinally into the pressure tank 2.

The front end of the nozzle body 21 forms a valve seat 14 whichinteracts with a-closing body 12. This closing body 12 is preferablydesigned as a ball and mounted in a flow channel 13 of a piston 9. Thispiston 9 has a guide part 18 which is sealed displaceably in relation tothe housing 7 by a seal 29. Moreover, the guide part 18 is likewisesealed displaceably in relation to the nozzle body 21 by a further seal28. As can be seen, the seal 28 is located directly behind the valveseat 14. The piston 9 is consequently guided displaceably in thedirection of the channel 15 in a limitable way.

An insert 32, in which a further closing body 11 which closes a passage33 (FIG. 4) is mounted, is inserted into the guide part 18. According toFIG. 4, this passage 33 connects passages 10 of the insert 32 to theflow channel 13.

Moreover, the pressure-reducing valve 27 comprises a pressure spring 16,which is designed as a helical spring and is supported at one end on anadjusting means 17 and at the other end on the guide part 18 of thepiston 9. As can be seen, the adjusting means 17 is of ring-shapeddesign and forms a counterbearing for the pressure spring 16. As can beseen, the adjusting means surrounds the nozzle body 21 and is guideddisplaceably on a cylindrical inner surface 34 of the housing 6.

The prestress of the pressure spring 16 can be adjusted by moving ordisplacing the adjusting means 17. For this purpose, the adjusting means17 has at least one projection 22, which, according to FIG. 5, isaccessible through a window 19 of the housing 6. According to FIGS. 5 to7, recesses 20, 23 and 24, which in each case form a seat for aprojection 22, are arranged in this window 19. The recesses 20, 23 and24 are designed in such a way that the corresponding positions of theprojection 22 are offset in the form of steps in the longitudinaldirection of the channel 15. The recess 20 shown in FIG. 5 forms a firstposition, in which the adjusting means 17 is furthest away from themouth 14. In this position, the prestress of the pressure spring 16 isat its lowest. With appropriate positioning of the projection 22 in therecess 23, this recess 23 produces a medium prestress, and the recess 24produces the greatest prestress of the pressure spring 16. The adjustingmeans 17 can be displaced between these three positions. This iseffected by the adjusting means 17 being taken hold of on the twoprojections 22, unlocked by turning, displaced and locked again byturning once more. In principle, more or fewer steps are also possible.It is moreover conceivable to make possible continuous displacement, forexample by means of a thread. However, the step arrangement makesadjustment easier.

With the pressure tank 2 filled with water, the internal pressure of thepressure space 3 acts via the opening 8 mentioned above on the outersurface indicated by B in FIG. 4 of the piston 9. In FIG. 3, the arrow26 indicates the direction in which the internal pressure of thepressure tank 2 acts on the piston 9. The pressure on the piston 9 is sogreat that the force of the pressure spring 16 is overcome and theclosing body 12 is held on the valve seat 4. In this position, the mouth4 of the channel 15 is closed. Moreover, the closing body 11 bearsagainst the passage 33 and closes it.

When a flush is initiated, the compressed air in the pressure space 3expands and the pressure on the surface B of the piston 9 is accordinglyreduced. When the pressure falls below a given level, the pressurespring 16 moves the piston 9 to the left in. FIG. 3 into the positionshown in FIG. 4. Accordingly, the closing body 12 is moved away to theleft from the mouth 14, and the closing body 11 is likewise moved awayto the left from the passage 33. Water can then flow into the flowchannel 13 through the channel 15. From this flow channel 13, the waterflows around the closing body 12 and passes through the passage 33 andthe lateral passages 10 to the opening 8 and finally through the pipe 30into the pressure space 3 of the pressure tank 2. If the outlet valve(not shown here) in the bottom of the pressure, tank 2 is closed, thepressure space 3 fills with water and the air contained therein isaccordingly compressed. Once the designated pressure of for example 1.5,2 or 2.5 bar has built up in the pressure space 3, a correspondingpressure acts on the piston 9. As the surface B is considerably largerthan an inner surface A (FIG. 4) of the piston 9, a force finallyresults which moves the piston 9 to the right in FIG. 4 into theposition shown in FIG. 3. This closing force is dependent on theprestress of the pressure spring 16, or the adjusted position of theadjusting means 17. If the adjusting means 17 are in the positionaccording to FIG. 5 for example, the pressure-reducing valve 27 closesat 1.5 bar for example. The medium closing pressure is 2 bar forexample, and the highest closing pressure 2.5 bar. When the mouth 4 isclosed by the closing body 12, the closing body 11 is also displaced onaccount of the pressure and thus closes the passage 33. This maximumpressure is maintained until a flush is initiated again. Subsequently,the operations mentioned above are repeated, that is thepressure-reducing valve 27 is opened again until a maximum designatedpressure is achieved. If a maximum pressure once adjusted is to bechanged, the adjusting means 17 are, as mentioned above, moved intoanother position by hand. As no parts have to be exchanged or replacedhere, such a change of the maximum pressure is possible simply andwithout further action. This results in both easier assembly, inparticular, but also in easier stockkeeping as no exchange parts have tobe kept in stock.

LIST OF REFERENCES

-   1 pressure-flushing cistern-   2 pressure tank-   3 pressure space-   4 mouth-   5 connection-   6 housing-   7 housing (cap)-   8 opening-   9 piston-   10 passage-   11 first closing body-   12 second closing body-   13 flow channel-   14 valve seat-   15 channel-   16 pressure spring-   17 adjusting means (ring)-   18 guide part-   19 window-   20 recess-   21 nozzle body-   22 projection-   23 recess-   24 recess-   25 system separator-   26 arrow-   27 pressure-reducing valve-   28 seal-   29 seal-   30 pipe-   31 opening-   32 insert-   33 passage-   34 inner surface-   A piston surface (small)-   B piston surface (large)

1-7. (canceled)
 8. Pressure-flushing cistern for a water closet, with apressure tank, an actuating device for initiating a flush, apressure-reducing valve, which is to be connected to a water pipe andvia which the pressure tank can be filled with flushing water, and withan outlet valve, wherein the closing pressure of the pressure-reducingvalve is adjustable.
 9. Cistern according to claim 8, characterized inthat the closing force of a counterpressure spring of thepressure-reducing valve is adjustable.
 10. Cistern according to claim 8,characterized in that the adjusting means are designed as a ring andthis ring forms a counterbearing for the pressure spring.
 11. Cisternaccording to claim 8, characterized in that the closing pressure can beadjusted by steps or continuously.
 12. Cistern according to claim 8,characterized in that the adjusting means are arranged on the peripheryof a nozzle body.
 13. Cistern according to claim 8, characterized inthat the pressure-reducing valve is arranged at the outlet of a systemseparator.
 14. Cistern according to claim 8, characterized in that thepressure-reducing valve comprises in a housing at least one lateralwindow through which the adjusting means are accessible or can begripped for adjusting the closing pressure.